Pneumatic drilling end effector

ABSTRACT

An end effector having a platform and a motor coupled to the platform for driving a drilling member. A motor housing is coupled to the platform and includes a plurality of photogrammetry targets secured thereto. The photogrammetry targets are oriented so as to be readily detectable by a photogrammetry sensor for determining the orientation of the end effector and corresponding drilling member. A pressure foot member and pneumatic cylinders are operably coupled to the platform such that the pneumatic cylinders maintain a constant pressure upon the pressure foot member to provide material clamp up. A depth control device is also provided for accurately controlling the depth of the drilling member and preventing further drilling.

FIELD OF THE INVENTION

[0001] This invention relates to end effectors manipulated by roboticarms and, more particularly, to an end effector capable of applying aclamping force while drilling, sensing the surface of the work piece toaccommodate variations in distance, removing metal chips, delivering aspray mist of lubricant to a drill tip, and employing photogrammetryposition targeting.

BACKGROUND OF THE INVENTION

[0002] In a traditional manufacturing process, manipulation andprocessing of products are typically accomplished manually by workers.In the case of modern aircraft manufacturing, this manual manipulationand processing frequently includes manually drilling a multitude ofholes through materials such as titanium and the like. The accuracy ofthese holes is highly dependent upon the skill of the worker. It is alsofrequently necessary to prepare these holes with countersunk sections toenable a fastener to lie generally flush with the material surface. Tothis end, it is necessary to maintain high tolerances and repeatabilityof drill depth in such applications. As can be appreciated, such work isextremely dependent upon the skill of the worker and also requiresenormous amounts of worker endurance. Accordingly, there exists a needin the relevant art to provide an end effector capable of expeditiouslydrilling numerous highly accurate fastener holes in a part.

[0003] Moreover, as mentioned above, aircraft manufacturing requireshigh tolerances to be maintained to ensure that the aircraft is able towithstand the rigors of flight. To this end, it is necessary to ensurethe depth and location of fastener holes are predictable and accurate,irrespective of the actual positioning of the part to be drilledrelative to the drilling apparatus. Accordingly, there exists a need inthe relevant art to provide an end effector capable of drilling numerousfastener holes within high tolerances.

[0004] Still further, titanium is frequently used in the manufacturingof aircraft. As is known to those skilled in the art, titanium is a verystrong and lightweight material particularly well suited for use instructurally demanding applications. However, due to the strengthcharacteristics of titanium, it is often necessary to provide alubricating fluid to the working tool in an attempt to extend the usefullife of the working tool. Accordingly, there exists a need in therelevant art to provide an end effector having a self-containedlubricating system.

[0005] Accordingly, it is a principal object of the present invention toprovide a drilling end effector capable of expeditiously drillingnumerous fastener holes in an aircraft.

[0006] It is another object of the present invention to provide adrilling end effector capable of drilling numerous fastener holes withinhigh tolerances.

[0007] It is another object of the present invention to provide adrilling end effector having a self-contained lubricating system.

[0008] It is yet another object of the present invention to provide adrilling end effector that is not susceptible to the shortcomings of theprior art methods.

SUMMARY OF THE INVENTION

[0009] The above and other objects are provided by a drilling endeffector in accordance with preferred embodiment of the presentinvention. Specifically, the end effector includes a platform and amotor coupled to the platform for driving a drilling member. A motorhousing is coupled to the platform and includes a plurality ofphotogrammetry targets secured thereto. The photogrammetry targets areoriented so as to be readily detectable by a photogrammetry sensor fordetermining the orientation of the end effector and correspondingdrilling member. A pressure foot member and pneumatic cylinders areoperably coupled to the platform such that the pneumatic cylindersmaintain a contstant pressure upon the pressure foot member to providematerial clamp up. A depth control device is also provided foraccurately controlling the depth of the drilling member and preventingfurther drilling.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The various advantages of the present invention will becomeapparent to one skilled in the art by reading the followingspecification and subjoined claims and by referencing the followingdrawing in which:

[0011]FIG. 1 is a perspective view illustrating a drilling end effectoraccording to a first embodiment of the present invention;

[0012]FIG. 2 is a plan view illustrating the drilling end effector ofFIG. 1;

[0013]FIG. 3 is an exploded perspective view illustrating the drillingend effector;

[0014]FIG. 4 is a plan view illustrating pneumatic cylinders withelements removed for clarity;

[0015]FIG. 5 is an enlarged perspective view illustrating a lowersection of the drilling end effector;

[0016]FIG. 6 is an enlarged cross sectional view illustrating the lowersection of the drilling end effector having portions removed forclarity;

[0017]FIG. 7 is a cross sectional view illustrating the adjustmentmechanism of the adjustable hard stop assembly;

[0018]FIG. 8 is a cross sectional view illustrating the vacuumattachment assembly;

[0019]FIG. 9 is an enlarged cross sectional view illustrating thelubrication system and chip blast system of the present invention;

[0020]FIG. 10 is an enlarged perspective view illustrating a lowersection of the drilling end effector according to a second embodiment ofthe present invention; and

[0021]FIG. 11 is an enlarged cross sectional view illustrating the lowersection of the drilling end effector of FIG. 10 having portions removedfor clarity

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Referring to FIGS. 1-3, a drilling end effector 10 is shownaccording to a first embodiment of the present invention having ahousing 12, a drill motor 14, pneumatic cylinders 16, a platform 18, aback plate 20, a tool changer interface plate 22, an adjustable hardstop assembly 24, a collet housing 28, and a vacuum attachment collarassembly 30. Drilling end effector 10 is adapted to be mounted to aconventional robotic arm assembly (not shown) for at least partialmanipulation thereby. Recently, robots have taken on an ever-increasingroll in the manufacture of complicated goods and the like.

[0023] It should first be understood that drilling end effector 10 ofthe present invention may be used in any orientation and, thus, anyreference to direction contained within this disclosure should beunderstood to apply to the drilling end effector being in an uprightposition or that position shown in the illustration.

[0024] Still referring to FIGS. 1-3, housing 12 is preferably anelongated member having a plurality of generally flat side panels 32.Housing 12 further includes a corresponding number of generally inclinedpanels 34. In the particular embodiment illustrated, inclined panels 34are each trapezoidal in shape such that they incline inwardly from sidepanels 32 and terminate in an end panel 36. End panel 36 is generallyoctagonal in shape as dictated by the particular geometricalconfiguration of the present embodiment. However, it should beunderstood that housing 12 might be of any shape conducive to theparticular environment or application in which the drilling end effectorwill be used.

[0025] Side panels 32, inclined panels 34, and end panel 36 of housing12 each further include at least one photogrammetry target 38 fixedlymounted thereto. In particular, each photogrammetry target 38 that ismounted to side panels 32 is secured using a generally angular bracket40. Angular bracket 40 is disposed such that photogrammetry targets 38are arranged in an orientation sufficient to be detected by aphotogrammetry sensor (not shown) in order to determine the position ofdrilling end effector 10 within the three-dimensional workspace.Preferably, photogrammetry targets 38 are spaced in angular orientation40-60 degrees around housing 12. Photogrammetry targets 38 arepreferably positioned on four vertical levels separated by approximately4½ inches. Further to this end, photogrammetry targets 38 are disposedupon inclined panels 34 and end panel 36 to provide additional targetsfor detection by the photogrammetry sensor from above. Testing has shownthat this orientation or distribution of photogrammetry targets 38enables precise positioning of drilling end effector 10 in space in sixdegrees of freedom (three linear and three rotational).

[0026] Housing 12 is secured to platform 18 and back plate 20 so as toprovide a rigid member for carrying photogrammetry targets 38 so as toaid in accurately determining the position and orientation of drillingend effector 10.

[0027] As best seen in FIG. 3, drill motor 14 is shown fixedly mountedto back plate 20 and platform 18. To this end, a mounting bracket 42includes a base support 44 that is securely mounted to back plate 20.Mounting bracket 42 includes a generally semi-circular portion 46 sizedto receive the generally cylindrical body of drill motor 14. Acorresponding semi-circular attachment member 48 is provided forsecuring drill motor 14 to mounting bracket 42. An optional pair ofwashers 50 is positioned between attachment member 48 and mountingbracket 42. A pair of fasteners (not shown), such as bolts, securesattachment member 48 to base support 44. This arrangement securelyretains drill motor 14 relative to back plate 20.

[0028] Referring now to FIGS. 1-3, tool changer interface plate 22 isfastened to back plate 20. Tool changer interface plate 22 is mateableto a tool changer (not shown) of the conventional robot arm assembly.Tool changer interface plate 22 acts as a manifold for compressed air tooperate drill motor 14, the drill feed mechanism, and the chip blast,and as a lubrication manifold for the lubrication system of drilling endeffector 10.

[0029] Referring in particular to FIGS. 3-5, pneumatic cylinders 16 areradially mounted to platform 18 and extending downwardly therefrom.Specifically, pneumatic cylinders 16 each include a slidable drive arm54 extending through a support 56 formed in platform 18. As will bedescribed in detail below, drive arms 54 are coupled to a pressure foot58 for applying a material clamping force through collet housing 28 to adrill bushing 60 and vacuum attachment collar assembly 30. In operation,pneumatic cylinders 16 exert a generally constant force of preferably 30p.s.i. As the robot arm assembly positions drilling end effector 10 inposition for drilling, pneumatic cylinders 16 are compressedapproximately 0.125″, thereby applying a uniform clamping pressurebetween drill bushing 60 and the underlying support structure supportingthe part being drilled.

[0030] As best seen in FIGS. 5, 6, and 9, adjustable hard stop assembly24 is shown having a quill nut 62, an electronic sensor 64, and anadjustable hard stop 66. Specifically, quill nut 62 is preferably a hexnut that is threadedly fastened to a quill 68 of drill motor 14. A jambnut 70 is further threadedly coupled to quill 68 of drill motor 14adjacent quill nut 62. Jamb nut 70 locks against quill nut 62 to preventunwanted axial movement of quill nut 62. Quill nut 62 further includes abore 72 formed in a lower face 74 thereof for receiving electronicsensor 64 therein.

[0031] Adjustable hard stop 66 is adjustably mounted within a centralbore 76 of pressure foot 58. Adjustable hard stop 66 includes a contactsurface 78, a pair of seal receiving channels 80, a threaded section 82,and a plurality of radially-spaced axially-extending grooves 84 (FIG.7). Contact surface 78 is adapted to contact quill nut 62 or quill 68 toprovide the hard stop. The pair of seal receiving channels 80 are eachdisposed generally radially about the exterior of adjustable hard stop66 and receive a seal 86 therein. Seal 86 engages adjustable hard stop66 and collet housing 28 to provide a sealing engagement to minimizedirt and debris therebetween. Threaded section 82 of adjustable hardstop 66 threadedly engages a corresponding threaded section 88 of collethousing 28. Preferably, threaded sections 82, 88 have a thread pitch of40 threads per inch. Rotation of adjustable hard stop 66 relative tocollet housing 28 enables contact surface 78 to be raised or lower topermit adjustment of the drill depth. As best seen in FIG. 7, a springloaded ball plunger 90 is slidably mounted in collet housing 28 andengages one of the plurality of radially-spaced, axially-extendinggrooves 84. Preferably, there are 25 radially-spaced, axially-extendinggrooves 84. Accordingly, this embodiment having 25 radially-spaced,axially-extending groove 84 and thread pitch of 40 threads per inchprovides axial drilling depth adjustment control of approximately0.001″. However, it should be understood that other combinations ofthread pitch and groove placement may be used to obtain unique depthadjustment control.

[0032] Electronic sensor 64 is preferably comprised of a copper buttonembedded in a nylon sleeve. A wire (not shown) attached to the copperbutton provides a continuous 24 VDC supply. During operation, as drillmotor 14 and, thus, quill 68 approach and contacts contact surface 78 ofadjustable hard stop 66, the copper button of electronic sensor 64contacts contact surface 78, thereby shorting to ground. This shortcauses a signal to be sent to the robot controller input/output board.When the signal indicating the drill has reached the end of the strokehas been received by the robot controller and after an optionalprogrammable delay, drill motor 14 retracts the drill and thus completesthe drilling cycle.

[0033] Collet housing 28 is coupled to pressure foot 58 via a pluralityof fasteners (not shown). Collet housing 28 is generally tubular inshape having an interior hollow portion sufficiently sized to receive acollet 94 slidably therethrough. Collet 94 is coaxially aligned andoperably coupled to drive motor 14 in a manner known in the art.

[0034] As best seen in FIG. 8, vacuum attachment collar assembly 30includes a vacuum attachment insert 96, a vacuum attachment 98, and acollar 100. Vacuum attachment insert 96 is generally cylindrical inshape so as to correspond to collet housing 28. Vacuum attachment insert96 is secured to collet housing 28 via a plurality of fasteners, such asspring ball plungers and corresponding detents or the like. The use ofspring ball plungers and detents permits easy engagement anddisengagement of vacuum attachment collar assembly 30 and furtherenables vacuum attachment collar assembly 30 to be used with multipleend effectors.

[0035] Vacuum attachment 98 is in turn coupled to vacuum attachmentinsert 96 via a known method, such as threaded coupling, welding, andthe like. Collar 100 extends from a lower end 104 of vacuum attachment98. Collar 100 is preferably made of a resilient material, such asrubber or bristled brushes, to enable collar 100 to engage and form aseal on a part to be drilled. Collar 100 thus serves to generally retainany debris and/or lubricant during the drilling process. Vacuumattachment 98 includes at least one vacuum hose connector 106 preferablyformed integral therewith and extending upwardly therefrom. Vacuum hoseconnector 106 is sized to be attached to a hose (not shown) of a vacuumfor removing debris and other materials from within vacuum attachment 98during the drilling process.

[0036] The present invention is particularly suited for drillingmaterials such as titanium. However, in order to maximize the drilllife, it is preferable to include a lubrication system and an air blastsystem for lubricating and cleaning the drilling bit. Moreover, it ispreferable to route lubrication and/or air blast pipes internally withinthe drilling effector to prevent damage during articulation of endeffector 10. Referring now to FIG. 9, a lubrication system 108 and anair blast system 110 are shown. Lubrication system 108 includes alubrication source 112 that is in fluid communication with a valvedevice 114 and a lubrication inlet passageway 116. Lubrication inletpassageway 116 extends through pressure foot 58. A lubrication outletpassageway 118 extends through drill bushing 60 and terminates near anexit end of drill bushing 60 so as lubricate drill bit 120. Anintermediate lubrication passageway 122 extends through collet housing28 and interconnects lubrication inlet passageway 116 and lubricationoutlet passageway 118, thereby defining a fluid path between lubricationsource 112 and the exit end of drill bushing 60 so as to providelubricating oil to drill bit 120 during a drilling operation.Preferably, lubrication source 112 is a lubrication unit providing mistoil employing compressed air and valve device 114 is a solenoid valve.

[0037] Still referring to FIG. 9, air blast system 110 includes acompressor or compressed air source 124 that is in fluid communicationwith a valve device 126 and an air inlet passageway 128. Air inletpassageway 128 extends through pressure foot 58. An air outletpassageway 130 extends through drill bushing 60 and terminates into achamber 132 near the exit end of drill bushing 60 so as provide an airblast to drill bit 120. An intermediate air passageway 134 extendsthrough collet housing 28 and interconnects air inlet passageway 128 andair outlet passageway 130, thereby defining a fluid path between airsource 124 and the exit end of drill bushing 60 so as to provide airblast to drill bit 120 during a drilling operation. The compressed airtravels from chamber 132 down the threads or flutes of drill bit 120 toclear the flutes of debris. It should be understood from the drawingsthat the compressed air combines with the lubricating oil to form alubricating mist at the tip of drill bit 120. Such lubricating mist isparticularly useful when drilling into metals such as titanium and thelike, where considerable amounts of heat is produced during the drillingprocess.

[0038] Briefly, during operation, drilling end effector 10 is positionedadjacent a part to be drilled by a robotic arm (not shown). The roboticarm positions drilling end effector 10 such that drill bushing 60 justcontacts the part to be drilled. The positioning of drilling endeffector 10 is determined and tracked in three-dimensional space by aphotogrammetry sensor which detects photogrammetry targets 38. Amicroprocessor or controller (not shown) thus manipulates drilling endeffector 10 relative to the part to be drilled without the use of jigsor other hard machining supports for determining position.

[0039] Pneumatic cylinders 16, having a constant pressure, act as airsprings to provide a clamping force to provide material clamp up. Thisoperation is capable of applying approximately 250 lbs of clamping forceaccording to the present embodiment. Once a predetermined clamping forceis achieved, drill bit 120 is then extended into engagement with thepart to be drilled. During this time, lubrication mist is introduced asa result of the combining of lubricant from lubrication system 108 andair from air blast system 110. This lubricating mist serves to cool,lubricate, and clean drill bit 120 during the drilling process. Thelubricating mist and any chips or other debris are vacuumed by vacuumattachment collar assembly 30. Drilling will continue until micrometer202 contacts switch input 220 of air logic switch 206, thereby sending acontrol signal to terminate the drilling operation.

[0040] During this process, the controller monitors the cycle timenecessary to drill each hole. This cycle time is then compared to aknown cycle length or to the first cycle length. By monitoring thiscycle time and comparing it to previous cycle times, an operator can beflagged that the drilling bit is beginning to dull or that othercomplications have arisen where the cycle lengthens.

[0041] The drilling end effector of the present invention provides anumber of advantages over the prior art. That is, the present inventionis capable, in part, of at least determining its position accuratelywithin a three dimensional space, providing its own feed axis (therebynot relying on the robotic arm), applying a clamping force whiledrilling, sensing the surface of the part to be drilled to accommodatevariations in distance between the drill bit and the part to ensuredepth repeatability, and lubricating and cleaning the drill bit whileworking in a confined area with no external pipes near the drilling bit.

[0042] According to a second embodiment of the present inventionillustrated in FIGS. 10 and 11, adjustable hard stop assembly 24 may bereplaced with a micrometer bracket assembly 200 to provide drillingdepth and/or countersink depth control of the drill bit 120. Micrometerbracket assembly 200 includes a micrometer 202, a micrometer bracket204, and an air logic switch 206. Micrometer bracket 204 is coupled to aquill 68 of drill motor 14. Specifically, micrometer bracket 204includes an aperture 208 sufficiently sized to surround quill 68 ofdrill motor 14. Preferably, a press fit connection exists betweenmicrometer bracket 204 and quill 68. To further retain micrometerbracket 204 in a stationary position relative to drill motor 14, athreaded nut 210 is threaded onto quill 68 of drill motor 14 to furtherretain micrometer bracket 204 on quill 68.

[0043] Micrometer 202 is further fastened to micrometer bracket 204. Tothis end, micrometer bracket 204 includes a support arm 212. Support arm212 includes an aperture 214 extending therebetween that is sized toreceive micrometer 202 therethrough. Preferably, aperture 214 creates apress fit with micrometer 202. More preferably, micrometer 202 isretained within aperture 214 of micrometer bracket 204 with a clampingpin extending between support arm 212 and, thereby, urging support arm212 together. This arrangement creates a higher retaining force forsecuring micrometer 202 relative to drill motor 14.

[0044] Micrometer 202 includes a measuring leg 216 extending downwardlytherefrom. Measuring leg 216 may be manually adjusted via a micrometercontrol knob 218 in a conventional manner. Air logic switch 206 isfixedly mounted to pressure foot 58 for movement therewith. Air logicswitch 206 includes a switch input 220 that is positioned directly belowmeasuring leg 216 of micrometer 202. In operation, micrometer 202, inconcert with air logic switch 206, provides an accurate means ofdetermining the exact extension or retraction of pressure foot 58 anddrill bushing 60 relative to drill motor 14 and back plate 20.Specifically, during operation drilling end effector 10 is moved intoposition adjacent the part to be worked such that drill bushing 60,collet housing 28, and pressure foot 58 are slightly depressed, therebyproviding material clamp up. During a drilling operation, micrometer 202approaches and eventually contacts switch input 220 of air logic switch206. Switch input 220, with pressurized air upstream, opens and sends anair signal to the robot controller to stop the drilling operation. Ithas been found that this system enables drill depth to be accurately andrepeatedly formed within approximately 0.002″.

[0045] Those skilled in the art can now appreciate from the foregoingdescription that the broad teachings of the present invention can beimplemented in a variety of forms. Therefore, while this invention hasbeen described in connection with particular examples thereof, the truescope of the invention should not be so limited since othermodifications will become apparent to the skilled practitioner upon astudy of the drawings, specification, and following claims.

1. A drilling end effector comprising: a platform; a motor coupled tosaid platform, said motor being operable to drive a drilling member; ahousing coupled to said platform, said housing substantially enclosingsaid motor; a plurality of photogrammetry targets secured to saidhousing, said plurality of photogrammetry targets being oriented uponsaid housing so as to be readily detectable by a photogrammetry sensorfor determining the orientation of the drilling end effector; a pressurefoot member; and an actuator operably coupled to said platform and saidpressure foot member to selectively extend said pressure foot memberrelative to said platform.
 2. The drilling end effector according toclaim 1 wherein said housing comprises: a plurality of outwardlyextending support members mounted to said housing, said plurality ofoutwardly extending support members having at least one of saidplurality of photogrammetry targets mounted thereon.
 3. The drilling endeffector according to claim 1, further comprising: a collet housingcoupled to said pressure foot; and a vacuum attachment assembly coupledto said collet housing, said vacuum attachment assembly adapted toremove debris during a drilling operation of the drilling end effector.4. The drilling end effector according to claim 3 wherein said vacuumattachment assembly comprises: a retaining ring portion mounted to saidcollet housing; a main body secured to said retaining ring portion, saidmain body having a hose attachment extending therefrom, said hoseattachment be mountable to a vacuum; and a collar extending from saidmain body, said collar engageable with a part to be drilled.
 5. Thedrilling end effector according to claim 1, further comprising: a depthcontrol device operable to determine a relative position between saidplatform and said pressure foot, said depth control device including: aprotruding member coupled to one of the group consisting essentially ofsaid platform, said motor, and said pressure foot; and a switch membercoupled to one of the other of the group consisting essentially of saidplatform, said motor, and said pressure foot, wherein said protrudingmember is operable to engage said switch member to provide a controlsignal when said platform is within a predetermined distance from saidpressure foot.
 6. The drilling end effector according to claim 5 whereinsaid protruding member is a micrometer.
 7. The drilling end effectoraccording to claim 3, further comprising: a drill bushing member securedto said collet housing, said drill bushing member operable to receivethe drilling member therethrough; a lubrication source; and a firstpassageway extending through said drill bushing member, said passagewaybeing in fluid communication with said lubrication source for deliveringa lubrication out of said drill bushing member.
 8. The drilling endeffector according to claim 7, further comprising: an pressurized airsource; and a second passageway extending through said drill bushingmember, said passageway being in fluid communication with saidpressurized air source for delivering pressurized air out of said drillbushing member.
 9. The drilling end effector according to claim 8wherein said first passageway and said second passageway are integrallyconnected to deliver a pressurized lubrication mist to the drillingmember.
 10. The drilling end effector according to claim 1, furthercomprising: a depth control device operable to control the depth of amachining operation, said depth control device including: a sensormember coupled to one of the group consisting essentially of saidplatform, said motor, and said pressure foot, said sensor member havinga sensor mounted thereon; and an axially-adjustable member coupled toone of the one of the other of the group consisting essentially of saidplatform, said motor, and said pressure foot, said axially-adjustablemember engagable with said sensor member to prevent further of saidmachining operation.
 11. A drilling end effector comprising: a platform;a motor coupled to said platform, said motor being operable to drive adrilling member; a housing coupled to said platform, said housingsubstantially enclosing said motor; a plurality of photogrammetrytargets secured to said housing, said plurality of photogrammetrytargets being oriented upon said housing so as to be readily detectableby a photogrammetry sensor for determining the orientation of thedrilling end effector; a pressure foot member; an actuator operablycoupled to said platform and said pressure foot member to selectivelyextend said pressure foot member relative to said platform; a collethousing coupled to said pressure foot; a vacuum attachment assemblycoupled to said collet housing, said vacuum attachment assembly adaptedto remove debris during a drilling operation of the drilling endeffector; and a depth control device operable to determine a relativeposition between said platform and said pressure foot.
 12. The drillingend effector according to claim 11 wherein said housing comprises: aplurality of outwardly extending support members mounted to saidhousing, said plurality of outwardly extending support members having atleast one of said plurality of photogrammetry targets mounted thereon.13. The drilling end effector according to claim 11 wherein said vacuumattachment assembly comprises: a retaining ring portion mounted to saidcollet housing; a main body secured to said retaining ring portion, saidmain body having a hose attachment extending therefrom, said hoseattachment be mountable to a vacuum; and a collar extending from saidmain body, said collar engageable with a part to be drilled.
 14. Thedrilling end effector according to claim 11 wherein said depth controldevice comprises: a micrometer coupled to one of the group consistingessentially of said platform, said motor, and said pressure foot; and aswitch member coupled to one of the other of the group consistingessentially of said platform, said motor, and said pressure foot,wherein said switch member is operable to engage said micrometer toprovide a control signal when said platform is within a predetermineddistance from said pressure foot.
 15. The drilling end effectoraccording to claim 11 wherein said depth control device comprises: asensor member coupled to one of the group consisting essentially of saidplatform, said motor, and said pressure foot, said sensor member havinga sensor mounted thereon; and an axially-adjustable member coupled toone of the one of the other of the group consisting essentially of saidplatform, said motor, and said pressure foot, said axially-adjustablemember engagable with said sensor member to prevent further of saidmachining operation.
 16. The drilling end effector according to claim11, further comprising: a drill bushing member secured to said collethousing, said drill bushing member operable to receive the drillingmember therethrough; a lubrication source; and a first passagewayextending through said drill bushing member, said passageway being influid communication with said lubrication source for delivering alubrication out of said drill bushing member.
 17. The drilling endeffector according to claim 16, further comprising: a pressurized airsource; and a second passageway extending through said drill bushingmember, said passageway being in fluid communication with saidpressurized air source for delivering pressurized air out of said drillbushing member.
 18. The drilling end effector according to claim 17wherein said first passageway and said second passageway are integrallyconnected to deliver a pressurized lubrication mist to the drillingmember.
 19. A drilling apparatus for use with a robot, said drillingapparatus comprising: a platform; a motor coupled to said platform, saidmotor being operable to drive a drilling member; a housing coupled tosaid platform, said housing substantially enclosing said motor; aplurality of photogrammetry targets secured to said housing, saidplurality of photogrammetry targets being oriented upon said housing soas to be readily detectable by a photogrammetry sensor for determiningthe orientation of the drilling end effector; a pressure foot member; anactuator operably coupled to said platform and said pressure foot memberto selectively extend said pressure foot member relative to saidplatform; a collet housing coupled to said pressure foot; a vacuumattachment assembly coupled to said collet housing, said vacuumattachment assembly adapted to remove debris during a drilling operationof the drilling end effector; a micrometer operable to determine arelative position between said platform and said pressure foot, saidmicrometer coupled to one of the group consisting essentially of saidplatform, said motor, and said pressure foot; and a switch membercoupled to one of the other of the group consisting essentially of saidplatform, said motor, and said pressure foot, said switch memberoutputting a control signal in response to contact from said micrometer.20. The drilling apparatus according to claim 19, further comprising: adrill bushing member secured to said collet housing, said drill bushingmember operable to receive the drilling member therethrough; alubrication source; a first passageway extending through said drillbushing member, said passageway being in fluid communication with saidlubrication source for delivering a lubrication out of said drillbushing member; a pressurized air source; and a second passagewayextending through said drill bushing member, said passageway being influid communication with said pressurized air source for deliveringpressurized air out of said drill bushing member.